Light-emitting apparatus and light-emitting apparatus system

ABSTRACT

A light-emitting apparatus includes: a first light guide which includes a first photoreceptor, a second photoreceptor, and a leak, the first light guide guiding light radiated by a radiation apparatus and received by the first photoreceptor and the second photoreceptor, the leak allowing leakage light to be leaked out, the leakage light being part of the light; a converter which converts a wavelength of the leakage light leaked out of the first light guide; a second light guide which is disposed along the first light guide, the second light guide guiding the light radiated by the radiation apparatus and received by a third photoreceptor to the second photoreceptor; and a protector which is tubular and in which the first light guide and the second light guide are disposed such that the first photoreceptor and the third photoreceptor are disposed at a same open end.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority of Japanese PatentApplication Number 2016-148989 filed on Jul. 28, 2016, the entirecontent of which is hereby incorporated by reference.

BACKGROUND 1. Technical Field

The present disclosure relates to a light-emitting apparatus whichlinearly emits light using laser light as a light source, and alight-emitting apparatus system.

2. Description of the Related Art

Conventionally, there has been a light-emitting apparatus which includesa leak that allows part of light guided into a light guide such as aoptical fiber to be leaked out, and which causes a phosphor around thelight guide to linearly emit visible light based on the leaked light.

For example, Patent Literature (PTL) 1 (Japanese Unexamined PatentApplication Publication No. H5-27121) discloses a technique forachieving surface emission by splitting, by a beam splitter, laserlight, into two beams, and causing the two beams of the split laserlight to enter the respective both ends of a light guide circularlyplaced.

Moreover, Patent Literature (PTL) 2 (Japanese Unexamined PatentApplication Publication No. 2006-3598) discloses a technique forreducing luminance unevenness of light emission in an extendingdirection of a light guide, by disposing a radiation apparatus whichradiates laser light at each of the both ends of the light guide, andcausing the both ends of the light guide to radiate laser light.

SUMMARY

Unfortunately, when a light guide is bent into an elongated U-shape andlight is linearly emitted by causing laser light to enter the both endsof the light guide, the both ends of the light guide which emit thestrongest light become one end of the whole, and the central part of thelight guide which emits the weakest light becomes another end of thewhole. In this case, it is not possible to reduce luminance unevenness.

On the other hand, when radiation apparatuses are disposed at the bothends of the light guide, it is necessary to dispose, along the lightguide, an electric wire for supplying power to the radiationapparatuses. In this case, the two radiation apparatuses make routing ofthe light guide difficult.

The present disclosure has an object to provide a light-emittingapparatus and a light-emitting apparatus system which not only ensureluminance evenness but also make routing of a light guide easy whenlight is linearly emitted using the light guide.

A light-emitting apparatus according to one aspect of the presentdisclosure is a light-emitting apparatus connected to a radiationapparatus which radiates laser light, the light-emitting apparatusincluding: a first light guide which includes a first photoreceptor atone end, a second photoreceptor another end, and a leak, the first lightguide guiding light radiated by the radiation apparatus and received bythe first photoreceptor and the second photoreceptor, the leak allowingleakage light to be leaked out in a direction crossing a light-guidingdirection, the leakage light being part of the light; a converter whichis disposed along the first light guide and converts a wavelength of theleakage light leaked out of the first light guide; a second light guidewhich is disposed along the first light guide, includes a thirdphotoreceptor, and does not include the leak, the second light guideguiding the light radiated by the radiation apparatus and received bythe third photoreceptor to the second photoreceptor; and a protectorwhich is tubular and in which the first light guide and the second lightguide are disposed such that the first photoreceptor and the thirdphotoreceptor are disposed at a same open end.

According to the present disclosure, when linear light is emitted usinga light guide, it is possible to ensure luminance evenness and improveroutability.

BRIEF DESCRIPTION OF DRAWINGS

The figures depict one or more implementations in accordance with thepresent teaching, by way of examples only, not by way of limitations. Inthe figures, like reference numerals refer to the same or similarelements.

FIG. 1 is a diagram illustrating the configuration of a light-emittingapparatus according to Embodiment 1, together with a radiationapparatus;

FIG. 2 is a cross-sectional view illustrating a state where thelight-emitting apparatus according to Embodiment 1 is cut along a planeperpendicular to an extending direction of a first light guide;

FIG. 3 is a cross-sectional view illustrating a cross section of thefirst light guide and a converter when cut perpendicular to alight-guiding direction of laser light;

FIG. 4 is a cross-sectional view illustrating a cross section of thefirst light guide and the converter when cut along the light-guidingdirection of the laser light;

FIG. 5 is a diagram illustrating, partially in a cross section, theconfiguration of a light-emitting apparatus according to Embodiment 2,together with a radiation apparatus; and

FIG. 6 is a cross-sectional view illustrating a state where thelight-emitting apparatus according to Embodiment 2 is cut along a planeperpendicular to an extending direction of a first light guide.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, a light-emitting apparatus according to an embodiment ofthe present disclosure will be described with reference to the drawings.It is to be noted that embodiments and variations to be described beloweach show a specific example of the present disclosure. The numericalvalues, shapes, materials, structural elements, the arrangement andconnection the structural elements, etc. indicated in the followingembodiments and variations are mere examples, and therefore do notintend to limit the present disclosure. Furthermore, among thestructural elements in the following embodiments and variations,structural elements not recited in any of the independent claims whichindicate the broadest concept of the present; disclosure are describedas optional structural elements.

It is also to be noted that the figures are schematic diagrams and arenot necessarily precise illustrations. Additionally, the same structuralelements are assigned the same reference signs in the figures, anddescriptions thereof may be omitted.

Embodiment 1

FIG. 1 is a diagram illustrating, partially in a cross section, theconfiguration of a light-emitting apparatus according to Embodiment 1.

FIG. 2 is a cross-sectional view illustrating a state where thelight-emitting apparatus according to Embodiment 1 is cut along a planeperpendicular to an extending direction of a first light guide.

As illustrated in these figures, light-emitting apparatus 100 accordingto Embodiment 1 illuminates a predetermined space in, for example, abuilding, a mobile body, an outdoor place, or the like, is used as anindicator lamp, a neon sign, or the like, and is connected to radiationapparatus 200 which radiates laser light. In Embodiment 1,light-emitting apparatus 100 includes first light guide 101, secondlight guide 102, converter 103, protector 105, and return 104.

[Radiation Apparatus 200]

Radiation apparatus 200 generates laser light to be radiated toconverter 103. In Embodiment 1, radiation apparatus 200 includes atleast one laser element 201 (four laser elements 201 in Embodiment 1)which emits laser light of a short wavelength selected from ablue-violet to blue (430 nm to 490 nm) range such that converter 103radiates visible light of a long wavelength. Although laser element 201is not limited to a particular type, an element which oscillates laserusing a semiconductor can be given as an example. Each laser element 201of radiation apparatus 200 is connected in series to one power supply(not shown), and all laser elements 201 can be stopped from oscillatingat once by disconnecting tie power supply or cutting off a power supplyline. Laser elements 201 of radiation apparatus 200 are collectivelyhoused in one housing. In addition, radiation apparatus 200 includeswaveguide body 202 such that laser light radiated by a half of laserelements 201 reaches first photoreceptor 111 of first light guide 101,and laser light radiated by the other half of laser elements 201 reachesthird photoreceptor 121 of second light guide 102.

It is to be noted that radiation apparatus 200 may include a beamsplitter which splits laser light radiated by one laser element 201 intotwo beams of laser light, and may emit the two beams of laser lightsplit by the beam splitter to first photoreceptor 111 of first lightguide 101 and third photoreceptor 121 of second light guide 102,respectively.

[Configuration of Light-Emitting Apparatus] [First Light Guide 101]

FIG. 3 is a cross-sectional view illustrating a cross section of a firstlight guide and a converter when cut perpendicular to a light-guidingdirection of laser light.

FIG. 4 is a cross-sectional view illustrating a cross section of thefirst light guide and the converter when cut along the light-guidingdirection of laser light.

First light guide 101 is capable of guiding laser light radiated byradiation apparatus 200 along a linear path, and includes firstphotoreceptor 111 at one end and second photoreceptor 112 at anotherend. In addition, first light guide 101 guides the received laser lightand includes leak 113 which allows part of the guided laser light to beleaked out in a direction crossing the light-guiding direction.

In Embodiment 1, first light guide 101 is what is called an opticalfiber which is flexible (has flexibility), and includes core 114 andcladding 115. A higher refractive index is set for core 114 than forcladding 115, which allows first light guide 101 to keep laser lightinside core 114 by total reflection, and guide the laser light highlyefficiently. Core 114 and cladding 115 are made from a material which ishighly transmissive of laser light, such as quartz glass and a plasticmaterial like an acryl resin.

[Leak 113]

Leak 113 is a component or structure which allows part of laser lightguided by first light guide 101 and passing inside core 114 to be leakedout in a direction crossing the light guiding direction.

In Embodiment 1, leak 13 includes minute beads dispersed inside core114. The beads have a surface which scatters laser light, and part ofthe laser light scattered by leak 113 travels in a direction differentfrom the light-guiding direction, and passes through cladding 115 toleak out of first light guide 101.

It is to be noted that leak 113 is not limited to the beads dispersedinside core 114, and may be another component or structure. For example,leak 113 may be cavities (air bubbles) dispersed inside core 114. Inaddition, leak 113 may be a portion provided in part of cladding 115 andhaving a refractive index different from that of cladding 115 to avoidtotal reflection of laser light passing inside core 114.

[Converter 103]

Converter 103 is disposed along first light guide 101 and converts awavelength of laser light which leak 113 allows to be leaked out offirst light guide 101 in a direction crossing the light-guidingdirection. In Embodiment 1, converter 103 is what is called a remotephosphor including dispersed phosphor particles which emits fluorescencewhen excited by laser light leaked out of first light guide 101.Specifically, converter 103 can be exemplified as a component in whichphosphor particles are dispersed inside a transparent base material.Moreover, a base material of converter 103 is made of resin etc. whichis transparent to laser light and light radiated by phosphors, and bendsfollowing a change in the form of first light guide 101.

Although it is sufficient that converter 103 includes at least one typeof phosphor, in Embodiment 1, converter 103 includes multiple types ofphosphors. More specifically, in order to radiate light of a desiredcolor such as white light using, as excitation light, the laser light ofthe short wavelength received from radiation apparatus 200, converter103 includes, in an appropriate ratio, multiple types of phosphors whichemit beams of light of a wavelength longer than that of the laser lightand of colors such as red, yellow, and green. As stated above, the beamsof light having the desired colors can be radiated by the mixing of thebeams of light of different wavelengths radiated by the multiple typesof the phosphors excited by the laser light of the short wavelength.Here, the term “ratio” includes a ratio in which at least one number is0.

Although a method for disposing converter 103 along first light guide101 is not particularly limited, for example, converter 103 may beattached to first light guide 101 by applying a liquid base material(resin) containing phosphors onto the outer circumferential surface offirst light guide 101, or converter 103 having a sheet shape orcylindrical shape may be laminated onto first light guide 101.

It is to be noted that phosphors may be included in cladding 115 offirst light guide 101, and caused to serve as converter 103 and leak113.

It is to be noted that at least one of the concentration of phosphor andthe ratio among the multiple types of the phosphors may be gradually orcontinuously varied.

Moreover, converter 103 may include a function film for efficientlyirradiating the phosphors with laser light, a function film forefficiently radiating emitted visible light, or the like.

Furthermore, converter 103 may include cover 131 which protectsconverter 103 from scrapes and scratches. Although a method for formingcover 131 or disposing cover 131 around converter 103 is notparticularly limited, a thin flexible resin tube may be disposed inclose adhesion around converter 103. Moreover, cover 131 may be formedby applying a liquid resin onto converter 103 and hardening the resinusing ultraviolet radiation, heat, etc.

It is to be noted that cover 131 may include a scattering component orstructure which scatters laser light to reduce the coherence of laserlight leaked out of first light guide 101 and converter 103.

[Second Light Guide 102]

Like first light guide 101, second light guide 102 is capable of guidinglaser light radiated by radiation apparatus 200 along a linear path,includes third photoreceptor 121 which receives the laser light, at anend on the side of radiation apparatus 200, and allows secondphotoreceptor 121 of first light guide 101 to receive the laser light.Moreover, unlike first light guide 101, second light guide 102 does notdeliberately include leak 113. Furthermore, second light guide 102 isdisposed along first light guide 101. Here, that leak 113 isdeliberately included means artificially providing leak 113 in a lightguide such as disposing beads inside core 114 as in first light guide101.

In Embodiment 1, like first light guide 101, second light guide 102 isan optical fiber including core 114 and cladding 115. In addition,second light guide 102 includes curved portion 122 which is curved byapproximately the minimum bend radius, on the opposite side of thirdphotoreceptor 121, and the length of second light guide 102 includingcurved portion 122 is greater than that of first light guide 101.

[Protector 105]

Protector 105 is a flexible tubular component into which first lightguide 101 and second light guide 102 are inserted such that firstphotoreceptor 111 of first light guide 101 and third photoreceptor 121of second light guide 102 are disposed at the same opening end.Protector 105 allows second light guide 102 to be disposed along firstlight guide 101, and first light guide 101 and second light guide 102 toappear like one component which linearly emits light. In addition,protector 105 is capable of protecting first light guide 101 and secondlight guide 102 from a localized pressure or impact from the outside.

Although a material of or a method for producing protector 105 is notparticularly limited, protector 105 which can be produced by extrusionmolding and part or all of which is made of a transparent silicone resincan be given as an example.

In Embodiment 1, protector 105 includes partition 151 which partitions aspace inside protector 105 into first chamber 154 which houses firstlight to guide 101, and second chamber 155 which houses second lightguide 102. Moreover, a surrounding wall of protector 105 on the side offirst chamber 154 is transmissive portion 152 which is transparent andcapable of transmitting light emitted by converter 103, and asurrounding wall of protector 105 on the side of second chamber 155 islight blocking portion 153 which blocks light involuntarily leaked outof second light guide 102. With this, the light emitted by converter 103can be transmitted to the outside of protector 105. Furthermore,partition 151 allows first light guide 101 to avoid direct contact withsecond light guide 102 disposed along first light guide 101, and iscapable of reducing damage to these light guides and converter 103.

Moreover, a surface of partition 151 at least on the side of firstchamber 154 serves as a reflector which reflects light emitted byconverter 103 toward the outside of protector 105. Specifically,partition 151 is opaque white in color, and serves both as the reflectorwhich reflects the light emitted by converter 103, and as thelight-blocking portion which blocks the light involuntarily leaked outof second light guide 102.

With this, it is possible to distribute, to the surrounding wall on theside of first chamber 154, light almost evenly emitted in all directionsby converter 103 in a plane perpendicular to an extending direction offirst light guide 101. In addition, it is possible to achieve a desiredcolor temperature by preventing light leaked out of second light guide102 being mixed.

Furthermore, the surrounding wall of protector 105 on the side of firstchamber 154 includes a scattering portion which scatters laser light.With this, it is possible to reduce the coherence of laser lightinvoluntarily emitted by a break of first light guide 101, and improvesafety for the human eye. The scattering portion is not particularlylimited, and fine particles may be dispersed in transmissive portion 152which is the surrounding wall of protector 105 on the side of firstchamber 154 or a minute uneven structure may be formed on the externalwall surface to scatter laser light.

It is to be noted that examples of a method for producing protector 105which includes partition 151 and of which the surrounding wall isdivided into transmissive portion 152 and light-blocking portion 153include coinjection molding which integrally extrudes different types ofresins.

[Return 104]

Return 104 is disposed on the side of second photoreceptor 112 of firstlight guide 101, and turns back laser light guided by second light guide102. In Embodiment 1, return 104 is a highly rigid component whichmaintains a curved state of curved portion 122 resulting from an endopposite third photoreceptor 121 of second light guide 102 being curvedby approximately the minimum bend radius, and which protects curvedportion 122 from pressure etc. exerted from the outside. Here, theminimum bend radius of second light guide 102 refers to the minimum bendradius which allows the loss of guided light caused by bending secondlight guide 102 to be within an allowable range, and is exemplified asbeing approximately 10 times the diameter of second light guide 102. Itis to be noted that the minimum bending radius depends on types or thelike of components (e.g., a core and a cladding) included in secondlight guide 102.

[Advantageous Effects]

As described above, light-emitting apparatus 100 according to thepresent embodiment makes it possible to easily handle a light-emittingcomponent which linearly emits light, by causing protector 105 tocollectively protect first light guide 101, converter 103 disposed alongfirst light guide 101, and second light guide 102. Moreover, because oneend of light-emitting apparatus 100 is connected to radiation apparatus200 and another end of the same can be freely moved, it is possible tofreely dispose light-emitting apparatus 100, and cause light-emittingapparatus 100 to emit linear light in any pattern such as a character.Here, the term linear refers not only to rectilinear but also to curved,meandering, zigzag, annular, etc. Moreover, because laser light isreceived by each of first photoreceptor 111 and second photoreceptor 112and guided in an opposite direction, light-emitting apparatus 100 makesit possible to reduce luminance unevenness of the visible light in theextending direction of first light guide 101.

Moreover, because return component 104 protects curved portion 122 ofsecond light guide 102 which has relatively inadequate structuralstrength, it is possible to increase the structural strength of wholelight-emitting apparatus 100 and to dispose light-emitting apparatus 100on a floor surface or the like to which pressure is applied from theoutside.

Embodiment 2

Next, another embodiment of light-emitting apparatus 100 will bedescribed. It is to be noted that the same reference signs are assignedto components (portions) having the same operation, function, shape,mechanism, or structure as in Embodiment 1, and description thereof maybe omitted. Moreover, hereinafter, description will center on pointsdifferent from those of Embodiment 1, and description of the identicalmatters may be omitted.

FIG. 5 is a diagram illustrating, partially in a cross section, theconfiguration of a light-emitting apparatus according to Embodiment 2.

As illustrated in the figure, light-emitting apparatus 100 according toEmbodiment 2 is connected to radiation apparatus 200 which radiateslaser light, as in Embodiment 1, and includes first light guide 101,second light guide 102, converter 103, and return 104. Moreover,light-emitting apparatus 100 includes protector 105.

[First Light Guide 101]

First light guide 101 according to Embodiment 2 is the same as the onein Embodiment 1. It is to be noted that in Embodiment 2, converter 103is not attached to first light guide 101.

[Second Light Guide 102]

Second light guide 102 according to Embodiment 2 does not include curvedportion 122 and has an end which is opposite third photoreceptor 121 andconnected to return 104. Moreover, second light guide 102 has almost thesame length as first light guide 101, because second light guide 102does not include curved portion 122.

[Converter 103]

As illustrated in FIG. 6, converter 103 is provided to the surroundingwall of protector 105 on the side of first chamber 154. Specifically,phosphor particles which are excited by laser light leaked out of firstlight guide 101 are dispersed in protector 105.

[Return 104]

Return 104 includes: reflector 141 which returns light radiated bysecond light guide 102, to second photoreceptor 112 of first light guide101, by reflecting the light; and cavity 142 through which laser lightpasses.

Reflector 141 is a mirror capable of reflecting laser light radiated byradiation apparatus 200. In Embodiment 2, two reflectors 141 areseparately provided inside return 104 so as to cause laser light emittedby second light guide 102 to enter second photoreceptor 112 byreflecting the laser light twice. Moreover, cavity 142 is formed in aU-shape inside return 104 so as not to interfere with the laser lightreflected by reflectors 141.

Moreover, protector 105 is bonded to return 104 at one end of protector105. This makes it possible to protect first light guide 101 and secondlight guide 102 more firmly.

[Advantageous Effects]

As described above, light-emitting apparatus 100 according to Embodiment2 produces the following advantageous effects in addition to or insteadof the advantageous effects produced by light-emitting apparatus 100according Embodiment 1.

Because return component 104 including reflector 141 makes it possibleto return laser light emitted by second light guide to secondphotoreceptor 112 of first light guide 101 regardless of the minimumbend radius of second light guide 102 or the like, it is possible todispose second light guide 102 in the proximity of first light guide101.

[Others]

It is to be noted that the present invention is not limited to theaforementioned embodiments. For example, other embodiments which can berealized by combing any of the structural elements described in thepresent description or by excluding some of the structural elements maybe embodiments of the present invention. Furthermore, variationsobtainable through various modifications to the aforementionedembodiments which can be conceived by a person skilled in the artwithout departing from the essence of the present invention, that is,the meaning of the recitations in the claims are included in the presentinvention.

For example, although first chamber 154 and second chamber 155 intowhich first light guide 101 and second light guide 102 are insertedrespectively are illustrated as being large relative to the diameter ofthese light guides, protector 105 may hold at least one of first lightguide 101 and second light guide 102 in close adhesion.

Moreover, although reflector 141 has been described as being integralwith partition 151, for example, a tape-like film on which metal isdeposited and which has high reflecting properties may be inserted intoprotector 105 and be used as reflector 141.

Furthermore, instead of causing the surrounding wall of protector 105which forms second chamber 155 to serve as light-blocking portion 153, atubular component which can be inserted into protector 105 and haslight-blocking properties may be used as light-blocking portion 153. Inthis case, the inside of the tubular component forms second chamber 155,and a surrounding wall of the tubular component also serves as partition151.

Moreover, irregularities for controlling light distribution may beformed in the outer surface or inner surface of protector 105, and acomponent including irregularities may be separately attached toprotector 105.

While the foregoing has described one or more embodiments and/or otherexamples, it is understood that various modifications may be madetherein and that the subject matter disclosed herein may be implementedin various forms and examples, and that, they may be applied in numerousapplications, only some of which have been described herein. It isintended by the following claims to claim any and all modifications andvariations that fall within the true scope of the present teachings.

What is claimed is:
 1. A light-emitting apparatus connected to aradiation apparatus which radiates laser light, the light-emittingapparatus comprising: a first light guide which includes a firstphotoreceptor at one end, a second photoreceptor at another end, and aleak, the first light guide guiding light radiated by the radiationapparatus and received by the first photoreceptor and the secondphotoreceptor, the leak allowing leakage light to be leaked out in adirection crossing a light-guiding direction, the leakage light beingpart of the light; a converter which is disposed along the first lightguide and converts a wavelength of the leakage light leaked out of thefirst light guide; a second light guide which is disposed along thefirst light guide, includes a third photoreceptor, and does not includethe leak, the second light guide guiding the light radiated by theradiation apparatus and received by the third photoreceptor to thesecond photoreceptor; and a protector which is tubular and in which thefirst light guide and the second light guide are disposed such that thefirst photoreceptor and the third photoreceptor are disposed at a sameopen end.
 2. The light-emitting apparatus according to claim 1, whereinthe protector includes a partition which partitions a space inside theprotector into a first chamber which houses the first light guide and asecond chamber which houses the second light guide.
 3. Thelight-emitting apparatus according to claim 2, wherein the protectorincludes a light-blocking portion which blocks light leaked out of thesecond light guide.
 4. The light-emitting apparatus according to claim1, wherein the protector includes a reflector which reflects lightemitted by the converter, toward an outside of the protector.
 5. Thelight-emitting apparatus according to claim 1, wherein the protectorincludes the converter in a surrounding wall on a side of the firstchamber.
 6. The light-emitting apparatus according to claim 1, whereinthe protector includes a scattering portion which scatters the laserlight toward the first chamber.
 7. The light-emitting apparatusaccording to claim 1, further comprising a return which is disposed on aside of the second photoreceptor of the first light guide and turns backlight guided by the second light guide.
 8. The light-emitting apparatusaccording to claim 7, wherein the return is connected to an end of theprotector.
 9. A light-emitting apparatus system, comprising: a radiationapparatus which radiates laser light; a first light guide which includesa first photoreceptor at one end, a second photoreceptor at another end,and a leak, the first light guide guiding light radiated by theradiation apparatus and received by the first photoreceptor and thesecond photoreceptor, the leak allowing leakage light to be leaked outin a direction crossing a light-guiding direction, the leakage lightbeing part of the light; a converter which is disposed along the firstlight guide and converts a wavelength of the leakage light leaked out ofthe first light guide; a second light guide which is disposed along thefirst light guide, includes a third photoreceptor, and does not includethe leak, the second light guide guiding the light radiated by theradiation apparatus and received by the third photoreceptor to thesecond photoreceptor; and a protector which is tubular and in which thefirst light guide and the second light guide are disposed such that thefirst photoreceptor and the third photoreceptor are disposed at the sameopen end.